As is well known in the railway art, brake actuators in railroad cars receive vibrations from the wheels of the cars and from the railroad tracks that the wheels travel on. Certain types of slack adjusters currently employed in brake actuators on passenger railway vehicles use a circumferential solid steel bushing located in front of other components of the slack adjuster to hold the components in place about the mechanism of the brake actuator. In addition, a wave washer is located between the steel bushing and a bearing race of the slack adjuster for absorbing axial vibrations received by the slack adjuster. The wave washer, however, is not an effective absorber and dissipater of the energy of axial vibrations, as it has a history of breaking apart under the axial forces generated by these vibrations.
Axial vibrations can also break ball bearings in the slack adjuster held in place between opposed bearing races. Bits and pieces of the bearings and wave washer are thus found in the slack adjuster and the brake actuator mechanisms, which bits and pieces can cause slack adjuster and brake actuator failure.